WASHINGTON — When Senator Bernie Sanders was tapped last year to head the Veterans Affairs Committee, the famed antiwar agitator and avowed socialist quickly emerged as a leading defender of those who served in uniform, calling it “a moral responsibility” to ensure they “get the best quality health care that we can possibly provide.”

But after serious mismanagement in the US Department of Veterans Affairs — and evidence that 18 veterans died while placed on secret waiting lists — the Vermont independent has come under fire from some veterans groups that say he has defended the government-run system too strongly.

The 72-year-old lawmaker’s stance, which is heavily influenced by his longtime support for government health care for all, has led some to accuse him of being blinded by ideology and not sufficiently using his oversight authority to force changes.

“I don’t think chairman Sanders has been effective. He has become an apologist for the VA,” said Paul Reickhoff, executive director of Iraq and Afghanistan Veterans of America, the largest veterans group representing veterans who served after the terrorist attacks of Sept. 11, 2001. “It seems to have to do with his worldview. He seems to think that any kind of demand for accountability or criticism of the VA is an attack to dismantle the entire system. Nobody is saying that. We’re saying if you want VA to be supported, then make VA work.”

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In a recent interview, Sanders stressed that his defense of the overall veterans health care system does not mean he takes lightly the revelations that veterans who were placed on waiting lists for so-called outpatient specialty care may have died while waiting to see a specialist.

“The VA has its share of problems, no question,” Sanders said. “I am not here to tell you that the VA is perfect. That is absolutely not the case.”

The criticism of Sanders, along with stepped-up attacks by Republicans on the Obama administration over its handling of veterans issues, illustrates the extent to which the political debate about the government’s role in health care has infused the controversy over the Department of Veterans Affairs.

“This connects to the larger national debate about health care and the Affordable Care Act,” said Phillip Carter, director of the military, veterans, and society program at the Center for a New American Security, a Washington think tank. “For both Republicans and Democrats, the ability of the VA to run an effective health care system — which includes both providing care and allowing people into the system — matters.”

Last week Sanders ironed out a compromise with Senator John McCain of Arizona to that would give the VA greater authority to hold senior-level officials accountable and give veterans more choices to seek care in the private health system, especially if they are forced to wait for VA care. The measure passed the Senate 93 to 3 Wednesday and closely resembles a version approved by the House.

But in committee hearings and appearances on the Senate floor and in the media, Sanders more than any other leading figure has gone to great lengths to praise that which the VA health system does right.

“The most important question is, ‘Does VA provide good quality health care to the people that access it?’ ” he said in the interview. “In many areas it is better than the private system.”

He maintains that his impassioned defense of the VA system is driven by what he believes is an effort by conservatives to use the latest developments to ultimately gut what by definition is government-supplied health care.

He cited, for example, recent political ads comparing the problems at the VA to the Affordable Care Act, as well as calls by some to privatize the veterans health care system.

“Any objective observer would say ‘OK, well how do these guys ideologically feel about the Veterans Administration health care, which as you know is a 100 percent government program,’ ” Sanders said. “You’ve got this ideology out there, conservative ideology that doesn’t like government.”

Yet a number of veterans advocates expressed disappointment in Sanders’s overall approach.

Louis J. Celli Jr., director of the National Legislative Division at the American Legion said he believes the Senate has fallen down on the veterans issue.

“On the Senate side, you’re having a huge divide, a huge problem, with the ranking side and the minority side [not] working together.”

Sanders, for his part, expresses some new willingness to work with some of his critics to address the VA’s problems.

After reaching the compromise with McCain, he said in a statement, “While this is not the bill that I would have written, we have taken a significant step forward.”

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